Height of a Projectile. A stone is thrown directly upward from a height of 30ft with an initial velocity of 60ft/sec. The height of the stone t seconds after it has been thrown is given by the function

s(t)=-16t^2+60t+30. Determine the time at which the stone reaches its maximum height and find the maximum height.

s(t)=-16t^2+60t+30. Determine the time at which the stone reaches its maximum height and find the maximum height.